Art of cracking hydrocarbons



H. l.. Pl-:LZER 1,865,206

ART CRACKING HYDRQCARBONS June 28, 1932.

Filed Dec. 16, 1929 retreated aan@ ae, resa RY lh. PELZER, @E HIG-IL,INDIANA, ASSIGNOR T C REFENEN@ COM- EANY, Q1? NEW YORK, N. Y., .dCBEDRATION @F l' G EYDRUAE (91* .Application tiled December 1t, 1999.Serial No. 4114,85@

This invention relates to the manufacture or motor fuel gasolene havinga high critical compression.

The invention is of special value in con- 5 'unction with crackingoperations in which igh boiling hydrocarbon oil is heated to a highcracking temperature in the vapor phase for the production of gasolene,such Jfor example as are described in my application n led d une 13th,1927, Serial Number 198,621,

but the invention is also useful in conjunction with other types ofcracking operations in which high boiling hydrocarbon oil is heated to ahigh cracking temperature, upm wards of 950 h".

li have discovered that the products of the reaction between sulfuricacid andthe unsaturated hydrocarbon constituents of the gas mixturesproduced in such cracking operations include at least two types ofconstituents, the addition of which to gasolene trac tions imparts tothe resulting gasolene mixture a higher critical compression. @ne suchtype of these reaction products includes oxygenated compounds ofalcohol, aldehyde or etone character, and another such type of thesereaction products includes compounds formed as a result ofpolymerization of these unsaturated hydrocarbon constituents.

According to this invention, a hi h boiling hydrocarbon oil, higherAboiling t an gasolene, is subjected to a cracking temperature upwardsof 950 F. and a gas mixture iucluding unsaturated hydrocarbonconstituents is separated from the products of the cracking operation, ahydrocarbon composite including the unsaturated hydrocarbon constituentsof this gas mixture is subjected to treatment with sulfuric acid, thereaction products of this treatment are separated into two parts, acomposite acid mixture and a composite oil mixture remaining immisciblewith the acid mixture, a polymerized gasolene fraction is distilled fromthe separated composite oil mixture, the separated composite acidmixture is subjected to hydrolysis to produce a second composite oilmixture and an oxidized gas'olene fraction is distilled from thissecondcomposite oil mixture. Either or both of the composite polymerizedgasolene fraction and the composite oxidized gasolene fraction soproduced may he combined with the asolene condensate produced in thesame crac ingoperation or with other gasolene fractions, or either orboth of the composite polymerized gasolene fraction and the compositeoxidized gasolene fraction `may to. ether with the gasolene condensateprouced in the said cracking operation be combined with other gasolene'fractions to roduce a motor fuel gasolene having a 'gh criticalcompression.

The invention will be further described in connection with theaccompanying drawing, which illustrates, diagrammaticallyandconventionally, one formI of apparatus adated for carrying outone'embodiment of e process of the invention.

The receiver 1 of the apparatus illustrate in the accompanying drawingis connected through connection 18 to the condenser of apparatus inwhich a high boiling hydrocarbon oil, such as gas oil or kerosene forexample, is subjected to a cracking temperature upa' wards of 950 1F.For example, the receiver 75 1 may correspond to the receiver 93conneet-ed to the condenseiJSds in the apparatus illustrated in myapplication tiled d une 13th, 1927, Serial Number 198,621.

The gasolene condensate and the associated gas mixture produced in thecracking operation are discharged into the receiver 1 through connection8. An initial separation between the gasolene condensate and the gas.mixture including uncondensed vapors is edected in this receiver. Thegasolene condensate separated in the receiver 1 is pumped throughconnections 9 and 12 by means of pump 3 into the upper end of thescrubbing tower li, and the gas mixture separated in the receiver 1 isforced through connections 1? and 14 by means of compressor 2 into thelower end of the scrubbing tower 4, a pressure being maintained in thescrubbing tower d' materially higher than the pressure maintained in thereceiver 1. The scrubbed gas mixture is discharged from the upper endofthe scrubbing tower 4 thro h connection 15. The condensate mixturemcluding unsaturated hydrocarbon constituents absorbed 1.00

from the gas mixture in the scrubbing tower 4is discharged throughconnection 16 to the rectifying tower 5. 'This rectiying tower may beoperated under a pressure intermediate that maintained in the receiver 1and -that maintained in the scrubbing tower 4, or under a pressureapproximating that maintained in the scrubbing tower 4. A vapor mixturecontaining in high concentration unsaturated hydrocarbon constituentsabsorbed from the gas mixture subjected to scrubbing treatment in thescrubbing tower 4 is discharged from the upper end of the rectifyingtower 5 through connection 17' into the condenser 6. The condensate fromthis condenser is discharged into the receiver 7. Any gas remaininuncondensed is recycled through the scrub ing tower 4 by means ofconnection 18. The condensate collecting in the receiver 7 containingunsaturated h drocarbon constituents, such as propylene, butylene,amylene and in some cases even ethylene, in high concentration, issupplied to the mixing pump 10 through connection 19. The rectiyingtower 5 is shown as provided with a cooling coil 20 and a heating coil2l for purposes of control. A part of the condensate collecting in-thereceiver 7 may also be reintroduced into the upper end of the rectifyingtower 5 through connection 22 for purposes of control. A rectifiedgasolene condensate is discharged from the lower end of the rectifyingtower 5 through connections 45 and 47 and cooler 46.

In the cracking operation, the high boiling hydrocarbon oil may beheated to a cracking temperature in the range 950-1200 F., for example,under a pressure in the ran e 0-500 pounds per square inch, for examp e.The receiver 1 may be operated under atmospheric pressure or under somehigher pressure. The scrubbing tower 4 may be operated, for example,under a ressure u wards of 50 pounds per square inc higher t an thepressure maintained in the receiver 1 and up to 500 pounds per squareinch or more, for example. The rectifying tower 5 may be operated undera pressure approximating that maintained in the scrubbing tower 4 orunder some lower pressure.

The condensate containing unsaturated hydrocarbon constituents in highconcentration supplied to the mixing pump 10 through connection 19 is,in the mixing pump 10 and the conduit 23, subjected to treatment withstrong sulfuric acid supplied through connection 24. The length of theconduit 23 may be adjusted to provide an appropriate period of contactbetween the reacting materials, and the reacting materials may bemaintained under a pressure in the conduit 23 higher than thatmaintained in the separating tower 11 by means of valve 24. A part ofthe acid mixture collecting in the means of connection 25 through thepump 10 and the conduit 23 together with fresh acid supplied throughconnection 24 v and condensate supplied through connection 19. Theseparating tower 11 is shown as provided with a cooling coil 39 'forpurposes of control. The composite acid mixture and the composite oilmixture remaining immiscible with the acid mixture produced as a resultof the reaction effected in the mixing pump 10 and the conduit 23 areseparated in the separating tower 11, the composite acid mixture bemg-discharged through connection 26 and the composite oil mixture throughconnection 27. Any gas mixture remaining is discharged throughconnection 28.' 'The composite oil mixture discharged through connection27 is supplied to the still 29, to which a neutralizing agent may alsobe supplied through connection 30, and a composite polymerized gasolenefraction is distilled from this oil mixture therein, this compositepolymerized gasolene fraction being condensed in the condenser 31 anddischarged through connection 32. The composite acid mixture dischargedthrough connection 26 isy subjected to hydrolysis, in the mixing pump 33and the conduit 34, with water sup'- plied throu h connection 35. Theproducts of this hy rolysis are discharged into the ractionating tower36, in which the lower boiling components of these products aredistilled from the diluted acid mixture to form a second composite oilmixture condensed in the condenser 37. The fractionating tower 36 isprovided'with a heating coil 38 for eifecting this distillation. Thediluted acid mixture is discharged through connection 39, for example,to concentration apparatus from which strong acid may be returned to themixing pump 10 through connection 24. The second composite oil mixture,condensed in the condenser 37, is supplied through connection 40 to thestill 41, to which a drying agent may also be supplied throughconnection 42, and a composite oxidized gasolene fraction is distilledfrom this second oil mixture therein, this com osite oxidized gasolenefraction being con ensed in the condenser 43 and discharged throughconnection 44. l 4

The reaction between the sulfuric acid and the condensate containingunsaturated hydrocarbon constituents inV high concentration, effected inthe mixing pump 1 0 and the conduit 23, is advantageously carried outunder a pressure high enough and at a temperature low enough to maintainthe hydrocarbons present substantially in liquid phase. Sulfuric acid ofstren h corresponding to 50-100 'per cent. 2S04, for example, may beused; however, stronger acid promotes polymerization and it is ingeneral more advantageous to use sulfuric separating tower 11 may berecirculated byacid of a strength corresponding to upwards respondingapproximately to that required motor fuel theoretically to formsulphates of the unsaturated hydrocarbon constituents present is anappropriate proportion. The proportion of water used inthe hydrolysismay vary, for example, from 25 per cent. to 500 per cent. of thesulfuric acid used.

lSolutions or suspensions of caustic soda or hydrated lime in oil oroil-Water mixtures may be supplied to the still 29 throu h connection 30as neutralizing agents., austic soda, hydrated lime, and calciumcarbide, are

useful as a drying agent in the still 41 and may be supplied theretothrough connection 42 in suspension in oil. A gasolene fraction may alsobe supplied to the still 41 through connection 42 as a drying agent fordrying the distillate discharged through connection 44. The stills 29and 41, for example, may be arranged and operated generally as describedin Letters Patent Number 1,689,531, issued to Sinclair Renin Company,August 16th, 1927, on an application of Ernest B. Phillips and .l amesGr. Staord.

The rectied gasolene condensate, the composite polymerized gasolenefraction and the composite oxidized gasolene fraction are discharged, inthe-apparatus illustrated, through connections 37, 42 and 44,respectively, and the manifolded connections 48, 49 and 50, forcombination with each other or with other gasolene fractions, for theproduction of motor fuel gasolenes having a high critical compression,or for the production of a composite gasolene fraction for blendinglWith other gasolene fractions of lower critical compression for theproduction therefrom of gasolenes having a high critical cbmpression. l

rlhe receiver 1, the scrubbing tower 4, and

n the rectifying tower may be operated, for

example, as described in an application filed December 16, 1929. SerialNumber 414,419, by Eugene C. Herthel.

@ther absorbent media, instead of the gasolene condensate separated inthe receiver 1, however, may be used for the purpose of recovering theunsaturated hydrocarbon constituents from the gas mixture separated inthe receiver 1. For example, this gas mixture may be subjected to a`conventional scrubbing treatment With an absorbent oil and the absorbedunsaturated hydrocarbon constituents distilled therefrom subjected torectification for the production of a condensate conl gas oil.

taining unsaturated hydrocarbon constituents in high concentration to besupplied to the mixing pump through connection 19.

, The gas mixture discharged through connection may be subjected toscrubbing treatment, for the further recovery of unsaturated hydrocarbonconstituents, With sulfuric acid to be supplied to the mixing pump 10through connection 24 as described in an application filed December 16,1929, Serial Number 414,362, by Frank A. Apgar.,

` The following example will further illustrate the process of theinvention: gas oil is heated to a cracking temperature approximating1080o F. under a pressure approximating 100 pounds per square inch andthe resulting hot oil'products are subjected to fractionation-toseparate a gasolene fraction and associated low boiling vapors andgases. rlhis gasolene fraction is subjected to con densation and theresulting gasolene condensate and gas mixture are separated. Theseparated gas mixture is subjected'to a scrubbing treatment at atemperature approximating 80 h". under a pressure approximating 250pounds per square inch with the separated gasolene condensate. 'lheresulting gasolene condensate mixture is subjected to rectificationunder-a pressure approximating 110 pounds per square inch producing avapor mixture containing unsaturated hydrocarbon constituents in highconcentration and producing a rectified gasolene condensate having arelatively low vapor pressure. rlhe vapor mixture is condensed and thecondensate treated with per cent. by volume of 80 per cent. HZSO,sulfuric acid at a temperature approximating 80o F. and at a pressureapproximating 150 pounds per square inch. rllhe products of theresulting reaction are separated into a composite oil mixture and acomposite acid mixture. The composite oil mixture is neutralized Withcaustic soda and a` composite polymerized gasolene fraction is distilledtherefrom. rlhe composite acid mixture is diluted With 200 per cent. byVolume of Water and a composite polymerized oil fraction is distilledtherefrom and a composite polymergized gasolene fraction is redistilledfrom this distillate in the 'presence of caustic soda. ln this vmanner40H50 per cent. of a rectified Y gasolene condensate, 1-2 per cent. of acomposite polymerized gasolene fraction and 2-4 per cent. of a compositeoxidized gasolene fraction may be recovered from theoriginal ln carryingout the process of the invention, no separation of the severalunsaturated hydrocarbon constituents of the liquefied hydrocarbonssubjected to the treatment with` sulfuric acid is necessary and anynecessity for critical control of the acid treatment to avoidpolymerizationreactions and to maintain conditions appropriate tosulfating reactions is also avoided. Thus, although the process of theinvention embodies some elements of operation analogous to operationscarried out for the production, for example, of alcohols fromhydrocarbon gas mixtures, it is essentially different from suchoperations in eliminating features of operation which tend to increaseoperating expense to a point prohibitive in the manufacture of motorfuel gasolene.

I claim:

1. In the manufacture of motor fuel gasolene having a high criticalcompression, the improvement which comprises subjecting a high boilinghydrocarbon oil to a cracking temperature upwards of 950 F. andseparating a gas mixture including unsaturated hydrocarbon constituentsfrom the products of the cracln'ng operation, subjecting a hydrocarboncomposite including the Aunsaturated hydrocarbon constituents of thisgas mixture to vtreatment with sulfuric acid, separating the resultingcomposite acid mixture and composite oil mixture, distilling ap-olymerized gasolene fraction from the separated composite oil mixture,hydrolyzing the separated composite acid mixture to produce a secondcomposite oil mixture, distilling an oxidized gasolene fraction lfromthis second composite oil mixture, and combining the compositepolymerized gasolene fraction and the composite oxidized gasolenefraction so produced with a gasolene :Eraction of lower criticalcompression to produce a motor fuel gasolene having a high criticalcompression.

2. In the manufacture of motor fuel gasolene having a high criticalcompression, the improvement which comprises subjecting a high boilinghydrocarbon oil to a cracking temperature upwards of 950 F. andseparating a gasolene condensate and a gas mixture including unsaturatedhydrocarbon constituents from the products of the cracking operation,subjecting a hydrocarbon composite including the unsaturated hydrocarbonconstituentsl of this gas mixture to treatment with sulfuric acid,separating the resulting composite acid mixture and composite oilmixture, distilling a polymerized gasolene fraction from the separatedcomposite oil mixture, hydrolyzing the separated composite acid mixtureto produce a. second composite oil mixture, distilling an oxidizedgasolene fraction from this second composite oil mixture, and combiningthe composite polymerized gasolene fraction and the composite oxidizedgasolene fraction so produced with the gasolene condensate'to roduce amotor fuel gasolene having a 'gh critical compression..

In testimony whereof I aix my signature. I

HARRY L. PELZER.

